By Rick Smith
Josephine Wong is an astrophysicist who studies pulsar wind nebulae and writes software to help researchers maximize returns on their science data. She also plays violin in the Stanford Medicine Orchestra at Stanford University in California, mentors high school students, writes creative fiction, and edits content for the Stanford astrophysics website. Oh, and she also swims as part of a university swim team.
“Yeah, my calendar is pretty full,” she laughed.
Wong is a graduate research assistant at Stanford. Working with NASA’s IXPE (Imaging X-ray Polarimetry Explorer) team, she analyzes data and writes papers advancing human understanding of high-energy space phenomena. An expert coder, she also develops software to extract more information from IXPE data about polarized X-rays observed from distant, highly energetic objects called pulsar wind nebulae.
X-ray polarization tells scientists about the organization and alignment of electromagnetic waves at X-ray frequencies, expanding our knowledge about the physical processes taking place within black holes and other extreme regions of our universe.
Combining data from IXPE and NASA’s Chandra X-ray Observatory, a Stanford team including Wong led a 2023 study of the MSH 15-52 pulsar wind nebula, unveiling the “magnetic bones” of the nebula’s eerily hand-shaped structure. Their findings helped identify how the dead, collapsed star at the center of the nebula, called a pulsar, lives on via plumes of energized matter and antimatter particles.
One of Wong’s primary contributions to the published results was applying an analysis technique – one she has been developing as part of her doctoral project at Stanford – to the dataset to help refine and deliver optimal results.
“The angular-resolution telescope tends to blur distinct X-ray polarization sources,” she said. “The software refines how we separate the polarized X-rays originating in the pulsar itself from those of the surrounding wind nebula.”
Pulsar wind nebulae, and pulsars in general, continue to capture Wong’s imagination.
“We’ve been studying these objects for nearly 60 years, and we still have a lot of unanswered questions,” she said. “How are the magnetic fields structured? How does the wind nebula get energized and accelerated to relativistic speeds? What are the processes responsible for the intense pulsed radiation we see across space? IXPE is proving very useful in helping us answer those questions.”
Wong further contributed to new findings about PSR B0540-69, a pulsar in the Tarantula Nebula more than 160,000 light-years from Earth. She is also the lead author of a new paper about IXPE findings at the Crab Nebula. Her proposed study of another pulsar wind nebula – this one enshrouded in the supernova remnant Kes 75, the youngest in the Milky Way galaxy, just 19,000 light years from Earth – recently was accepted in the new IXPE General Observer Program, set to expand IXPE’s availability to a variety of academic research teams around the world.
Wong grew up in Los Angeles. Her parents emigrated from southern China and taught her Cantonese. Wong and her sister went to the local library often as kids, and that’s where she discovered her interest in science – biology, chemistry, and especially outer space. Then, in middle school, she read Kip Thorne’s “Black Holes and Time Warps” – and astronomy permanently took hold of her imagination.
“I was spellbound,” she said. “I knew then I wanted to do this work for the rest of my life.”
Even so, Wong earned a degree in electrical engineering in 2018 from Harvey Mudd College in Claremont, California, on the assumption that it would put her on a surer career path. She went to work for Northrop Grumman for the next two years, designing digital hardware for radio antenna communications. But the desire to pursue work among the stars refused to release its grip on her.
“I knew I’d regret it forever if I didn’t take a risk and pursue the job of my dreams,” she said. She took the Graduate Record Exam and was admitted to Stanford in 2020, where she’s now working to complete her doctorate.
Since fall 2021, Wong also has been involved in Stanford’s FAST (Future Advancers of Science and Technology) program. In the last two years, she has served as deputy program officer, planning workshops and organizing events, and as communications officer, maintaining the FAST website and handling all internal communications. As a mentor, she visits high schools in San Jose, California, working with students on year-long science fair projects, sharing advice about preparing for college and careers, and organizing the year-end FAST symposium, bringing participating students to Stanford to present their research projects. Wong’s pride in the results is palpable.
“I love teaching,” she said. “My parents never had a science background, so all the support and mentorship I enjoyed came from great teachers. By volunteering my time to FAST, I’m paying that forward, helping new generations achieve their dreams.”
One can’t help but imagine all the young future astrophysicists – and programmers and science writers and musicians – she’s inspiring along the way.
Smith, an Aeyon/MTS employee, supports the Office of Communications at NASA’s Marshall Space Flight Center, which leads the IXPE mission for NASA.